Paraules clau:: EU ETS; carbon price; cointegration; forecasting; permanent-transitory decomposition
Resum: This article studies the relationship between the prices of fuel and EU allowances (EUA) for carbon emissions during Phase III of the European Union Emissions Trading System. We find that the forward prices of EUA, coal, gas and Brent oil are jointly determined in equilibrium. The existence of such long-run relationship entails a permanent-transitory decomposition for the series of EUA and fuel prices that reveals the short and long-term causal influence of the EUA market in shaping the joint dynamics of fuel prices. This result complements the literature that suggests that EUA prices are driven by the dynamics of fuel prices. Interestingly, we do not find an equilibrium relationship in the spot market. EUA and fuel spot prices are driven by independent unit root processes. The differences between spot and forward markets are attributed to the tradability of forward prices that are used for speculation and hedging in financial markets. In contrast, spot prices are mainly driven by supply and demand in energy markets.